Most of you probably like the fact that Ubuntu Software Center is now used for opening .deb files in Ubuntu 10.10 Maverick Meerkat, but I for one am not very happy with this change because Ubuntu Software Center is a lot slower then GDebi so why wait some extra seconds when I can do it faster with GDebi?
Also, Ubuntu Software Center doesn't display the dependencies that will be installed with the .deb so if for instance I download some .deb for KDE and don't realize this, Ubuntu Software Center will install hundreds of packages while GDebi will display the number of dependencies that are about to be installed so this can be avoided:
If you want to use GDebi again instead of Ubuntu Software Center to install .deb files in Ubuntu 10.10 Maverick Meerkat, the "fix" is actually quite easy. Firstly, install these packages:
sudo apt-get install gdebi gdebi-core
Then right click a .deb file, select "Properties", go to the "Open With" tab and select "GDebi Package Installer" instead of "Ubuntu Software Center". Click "Close" and double click the .deb file - it should now open with GDebi and not Ubuntu Software Center.
Note: I only used Amarok as an example, I obviously know Amarok is a KDE application.
Info thanks to PortalUbuntu